The eAssist system becomes the standard powertrain on LaCrosse starting
next summer. The system uses a state-of-the-art lithium-ion battery system
and electric motor-generator to enable regenerative braking capability to
improve LaCrosse fuel economy by an estimated 25 percent.

"The LaCrosse with eAssist technology is the latest example of how this
successful car, with sales up more than 200 percent for the
year, is shaking up the segment and reinventing Buick," said
John Schwegman, vice president of Buick
marketing. "It is the smart choice for those who want great fuel economy
and performance in a luxury vehicle, with excellent value,
the LaCrosse with eAssist will cost thousands less than competitors with
similar technologies."

Regenerative braking, which provides up to 15 kW of electricity to
charge the battery

Providing up to 11 kW (15 hp) of electric power assistance during
acceleration

Automatic engine shut-off when the vehicle is stopped

Aggressive fuel cut-off during deceleration down to zero vehicle speed,
enabled by the torque smoothing provided by the motor-generator unit

Intelligent charge/discharge of the high-voltage battery.

Buick LaCrosse with eAssist technology
also features improved underbody aerodynamics and tires optimized for
performance and fuel economy, as well as active control of front-end
airflow that improves aerodynamics and engine warm-up. Electronically
controlled shutters in the lower grille close at higher speeds to push more
air over the vehicle, which increases aerodynamic efficiency to enhance
fuel economy. All of these technologies increase the eAssist system's
regenerative braking capability, while also improving the vehicle's
efficiency while driving.

"LaCrosse was the first in its segment with a four-cylinder/six-speed
powertrain, the first with HiPer Strut and is now is leading the way with
the new standard eAssist technology," said Schwegman. "Importantly,
LaCrosse with eAssist is the standard powertrain for four-cylinder-equipped
models and there isn't a cost premium."

LaCrosse with eAssist includes an ECO gauge on the instrument panel that
continuously responds to driving behavior, enabling the driver to drive
with maximum efficiency. It also features a hill-assist system that
captures brake pressure to help the driver more comfortably accelerate from
a stop on a moderate or steep grade. It does this by greatly reducing the
tendency of the vehicle to roll backward with the engine in shut-down
mode.

eAssist details

While the eAssist system shares the same basic belt-alternator-starter
configuration of previous BAS designs, it delivers more than three times
the power and is much more capable than the previous-generation BAS
system.

"The eAssist system is more than just the next-generation BAS system.
The ability to integrate regenerative braking with the latest lithium-ion
battery technology creates a system that delivers significant
fuel-efficiency gains that customers will enjoy," said Steve Poulos, global chief engineer of the eAssist
system. "Being able to provide electric boost to the powertrain system
during heavy acceleration and grade driving enables the LaCrosse
transmission to operate more efficiently, while the added functionality of
engine start-stop and fuel shut-off during deceleration provides added fuel
savings."

The eAssist system's 115V air-cooled lithium-ion battery bolsters the
2.4L Ecotec four-cylinder engine with approximately 11 kW (15 horsepower)
of electric power assist during heavy acceleration and 15 kW of
regenerative braking power. That compares with only 2 kW of power assist
and 5 kW of regenerative power on the previous BAS system. The greater
power capability enables greater energy capture during regenerative braking
for improved fuel economy.

The system also enables the Ecotec engine to shut down fuel delivery in
certain deceleration conditions, which saves additional fuel. While in fuel
shut-off mode, the motor-generator unit continues spinning along with the
engine to provide immediate and smooth take-off power when the driver
presses on the accelerator. Then, as the vehicle comes to a stop, the
motor-generator unit spins the engine, bringing it to a smooth stop
€“ properly positioned for a smooth restart.

"The battery system is designed to provide power assistance to the
internal combustion engine, rather than storing energy for all-electric
propulsion," said Poulos. "It's really an extension of the conventional
internal combustion engine, not a replacement for it."

The eAssist power pack contains the lithium-ion battery pack, the
integrated power inverter and 12V power supply. It is located in a
compartment between the rear seat and trunk; and it is surprisingly compact
and lightweight, weighing only about 65 pounds (29 kg). It still allows
rear access to the trunk via the split-folding rear seat €“ an
attribute not shared with other hybrid competitors. Trunk space is slightly
reduced when compared with 2011 models with the four-cylinder/six-speed
powertrain, but still offers 10.9 cubic feet (307 liters) of storage. An
electric fan cools the power pack, drawing air from a vent located in the
package tray, behind the rear seat. The fans are designed to be quiet from
the cabin.

The eAssist system's electric motor-generator is mounted to the engine
in place of the alternator to provide both motor assist and
electric-generating functions through a new engine belt-drive system. The
motor-generator is a high-performance, compact induction motor that is
liquid-cooled for increased performance and efficiency.

Next-generation six-speed

The eAssist system works with LaCrosse's direct injected 2.4L Ecotec
four-cylinder and next-generation six-speed automatic powertrain
combination. In the LaCrosse with eAssist, the engine is rated at
approximately 180 horsepower (134 kW) and the next-generation Hydra-Matic
6T40 takes transmission technology to the next level with features designed
to enhance powertrain efficiency.

Significant internal transmission changes to clutch controls and
hardware provide reduced spin losses while improving shift response and
time. The added electric power provided by the eAssist system allows for
higher gearing to improve steady state efficiency without impacting
acceleration performance or driveability. The system's capability of
providing some electric assistance at cruising speeds allows the driver to
accelerate lightly or ascend mild grades without the transmission
downshifting.

An auxiliary, electric-driven transmission oil pump is added to the
6T40, which keeps the transmission primed and the fluid flowing when the
engine shuts down at a stop. That keeps the transmission ready to perform
when the driver accelerates, for a seamless, uncompromised driving
experience.

"It's a very integrated powertrain system, with no compromises in
driving performance, shift quality or ride and handling," said Daryl Wilson, LaCrosse lead development engineer.
"We believe this combination points to the future of vehicles powered
primarily by an internal combustion engine."

About Buick

Buick is a modern luxury brand offering vehicles with sculpted designs,
luxurious interiors with thoughtful personal technologies, along with
responsive-yet-efficient performance. Buick is attracting new customers
with its portfolio of award-winning models, including the Enclave
crossover, LaCrosse sedan and Regal sport sedan. The new Buick Verano compact sedan and a small crossover
will join the portfolio in the next few years. Buick's sales continue to
increase in North America, and it remains
a best-selling brand in China, with
continuing record growth. Learn more about Buick cars and crossovers at
www.buick.com, on Twitter @buick or at www.facebook.com/buick.